Preparation of Bi-Based Ternary Oxide Photoanodes BiVO4, Bi2WO6, and Bi2Mo3O12 Using Dendritic Bi Metal Electrodes

The major limitation to investigating a variety of ternary oxides for use in solar energy conversion is the lack of synthesis methods to prepare them as high-quality electrodes. In this study, we demonstrate that Bi-based n-type ternary oxides, BiVO4, Bi2WO6, and Bi2Mo3O12, can be prepared as high-quality polycrystalline electrodes by mild chemical and thermal treatments of electrodeposited dendritic Bi films. The resulting oxide films have good coverage, adhesion, and electrical continuity, allowing for facile and accurate evaluation of these compounds for use in solar water oxidation. In particular, the BiVO4 electrode retained the porosity and nanocrystallinity of the original dendritic Bi film. This feature increased the electron-hole separation yield, making this compound more favorable for use as a photoanode in a photoelectrochemical cell.